The invention relates to a screw driving device as an accessory for an electrical hand tool such as a drilling device for setting screws or bolts in previously drilled holes and an associated working procedure.
According to DE4407155 a device is disclosed as an accessory for a drilling device for setting screws comprised of a screw magazine with a conveying strip that holds the screws.
According to DE3347323 a screw magazine with a conveying strip with screws comprising a axially displaceable feeder block that acts against the force of a feed spring, the block feeding screws successively with a back and forth reciprocating movement of the feeder block.
According to DE19745915 a screw driving device including a screw magazine is disclosed in which the feeding of the screws is synchronized with the screw driving process using a transport filament.
According to DE19727187 a screw driving device comprises a driving tool combined with an overload clutch, that has a limiting torque.
Such screw driving devices do not comprise a feature for first boring the holes in which the screws are set. This is especially necessary in hard materials and results in an additional preparatory work step. In addition self-tapping screws can be used instead of conventional screws.
According to DE3431630 an electrical hand tool that is so configured that it can be used either to drill or to drive comprises a switchable axially displaceable drill spindle with a clutch for transmission of torque, which when driving is disengaged via an axially cushioning pre-stressed drive depth stop at a torque that is dependent on the pressing force. A tool change is required between drilling and driving.
According to DE20018533U1 a drill is disclosed that comprises a drill bit that is configured as form-locking rotation driver element for screw heads. The wear on the drill tip when drilling results in an unsatisfactory rotation driver when driving screws.